This invention generally pertains to the field of urethane catalysts. More particularly, this invention relates to the purification of amine catalysts that incorporate a reactive hydrogen group.
Amines (mono and poly) are a typical type of catalyst used for making polyurethanes. For example, amines such as N,N,N′-trimethylbis(aminoethyl)ether are useful as a polyurethane catalyst or as a chemical intermediate. When trimethylbis(aminoethyl)ether is prepared N,N,N′,N′,-tetramethylbis(aminoethyl)ether is also made. Fractional distillation does not separate the trimethyl and tetramethyl compounds. The inventors have recognized that a need exists for a purification method of amines such as N,N,N′-trimethylbis(aminoethyl)ether to remove undesirable coproducts such as N,N,N′,N′,-tetramethylbis(aminoethyl)ether.